KR20190047632A - Composite particles, method of refining and use thereof - Google Patents

Abstract

The present invention relates to a composite particle, which provides improved planarity, and to a purification method, and a use thereof. The composite particle of the present invention comprises a silica core particle and a ceria nanoparticle, and is a ceria-coated silica particle.

Description

COMPOSITE PARTICLES, METHOD OF REFINING AND USE THEREOF FIELD OF THE INVENTION [0001]

Cross reference of related application

This application claims priority to U.S. Provisional Serial No. 62 / 577,978, filed October 27, 2017, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Chemical mechanical planarization (" CMP ") polishing compositions (CMP slurries, CMP compositions or CMP formulations are intermixed) are used in the manufacture of semiconductor devices. SUMMARY OF THE INVENTION The present invention is directed to a polishing composition comprising purified multiparticulates (used as abrasive particles) that are particularly suitable for polishing patterned semiconductor wafers comprising a silicon oxide material.

Silicon oxide is widely used as a dielectric material in the semiconductor industry. There are several CMP stages in integrated circuit (IC) manufacturing processes such as shallow trench isolation (STI), interlayer dielectric (ILD) CMP and gate poly CMP. Typical oxide CMP slurries contain abrasives in the presence of other chemicals. Other chemicals may be dispersants that improve slurry stability, boosters that increase the removal rate, or inhibitors that reduce the removal rate and stop other films, such as STI applications, on SiN.

A preferred feature of the CMP slurry in advanced semiconductor technology nodes is reduced wafer defects, high removal rates, very low wafer non-uniformity (WWNU) and low topography for removal rates. Having a very low WWNU for the removal rate is particularly important. The higher non-uniformity of the removal rate results in excessive polishing on the wafer area and less polishing when the minimum material is removed. This creates non-uniform topography on the wafer surface which is undesirable for semiconductor fabrication. Therefore, sufficient CMP process development in terms of pad, conditioning, and polishing zone pressure adjustment is required to form a desirable uniform removal rate profile.

Of the general abrasives used in CMP slurries such as silica, alumina, zirconia, titania and the like, ceria is well known for its high reactivity to silica oxides and has the highest oxide removal rate (RR) due to the high reactivity of ceria to silica, It is widely used in CMP slurries.

Cook et al. (Lee M. Cook, Journal of Non-Crystalline Solids 120 (1990) 152-171) proposed a 'chemical tooth' mechanism to explain the special properties of ceria. According to this mechanism, when ceria particles are pressed onto a silicon oxide film, the ceria breaks down the silica bond and forms a Ce-O-Si structure, thereby decomposing the silica from the surface.

Most of the ceria used in the CMP industry is manufactured from a calc-wet milling process. The resulting ceria has a sharp edge and a very wide size distribution. It also has a very large " large particle count " (LPC). All of these are believed to be responsible for defects and low yields, especially scratches after polishing the wafer. Various types of ceria-containing particles, such as colloidal ceria or ceria coated silica particles, are also being considered to address this challenge.

Ceria coated silica particles have been found to be particularly useful for achieving high removal rates of silicon oxide films while having a lower defect rate (PCT / US16 / 12993, US2016358790, US2017133236, US201783673). However, it is still necessary to further improve the removal rate, to adjust the wafer nonuniformity (WWNU), and to reduce abrasive defects.

The present invention relates to ceria-coated composite particles for abrasive applications capable of realizing performance requirements.

Accordingly, there is a significant need for CMP compositions, methods, and systems that can provide excellent wafer uniformity, higher removal rates and lower defects for removal rates.

Composite particles having a specific particle size distribution useful for making CMP polishing compositions, slurries, or formulations for polishing semiconductor wafers that provide improved planarity are described herein.

In one aspect, the present invention provides a chemical mechanical planarization (CMP) polishing composition comprising:

A composite particle comprising ceria-coated silica particles, wherein the particle size distribution width characterized by D50 / (D99-D50) is ≤ 1.85, preferably ≤ 1.50, more preferably ≤ 1.30, and most preferably less than 1.25 D99 is the particle size to which 99% by weight of the composite particles belong, D50 is from 0.01 to 20% by weight of the composite particles having a particle size to which 50% by weight of the composite particles belong;

A water-soluble solvent selected from the group consisting of water, a polar solvent, and a mixture of water and a polar solvent, wherein the polar solvent is selected from the group consisting of alcohol, ether, ketone or other polar reagent;

The pH of the CMP composition ranging from about 2 to about 12

And, optionally,

From 0.0001 wt.% To about 5 wt.% Of a pH adjusting agent selected from the group consisting of sodium hydroxide, cesium hydroxide, potassium hydroxide, cesium hydroxide, ammonium hydroxide, quaternary organic ammonium hydroxide, and combinations thereof;

Organic carboxylic acids, amino acids, aminocarboxylic acids, N-acylamino acids and salts thereof; Organic sulfonic acids and their salts; Organic phosphonic acids and their salts; Polymeric carboxylic acids and their salts; Polymeric sulfonic acids and their salts; Polymeric phosphonic acids and their salts; Selected from the group consisting of compounds having functional groups selected from the group consisting of arylamine, aminoalcohol, aliphatic amine, heterocyclic amine, hydroxamic acid, substituted phenol, sulfonamide, thiol, polyol having hydroxyl group and combinations thereof 0.000001 wt% to 5 wt% of a chemical additive;

a). Nonionic surface wetting agents, b). Anionic surface wetting agent, c). Cationic surface wetting agents, d). From about 0.0001 wt.% To about 10 wt.% Of a surfactant selected from the group consisting of amphoteric surface wetting agents, and mixtures thereof;

From 0.01% to 3.0% by weight of chelator;

Corrosion inhibitors;

Oxidant; And

Biological growth inhibitor

(CMP) < / RTI > polishing composition.

In another aspect, the present invention is a method of chemical mechanical planarization of a semiconductor device using the disclosed chemical mechanical planarization (CMP) polishing composition.

In another aspect, the present invention is a system for chemical mechanical planarization of a semiconductor device comprising the disclosed chemical mechanical planarization (CMP) polishing composition.

The average particle size (MPS) of the core particles may range from 10 nm to 500 nm, preferably from 20 nm to 200 nm, more preferably from 50 nm to 150 nm. The core particles are larger than the nanoparticles. The MPS of the core particle size in the multiparticulates can be measured by suitable imaging techniques, such as transmission electron microscopy imaging.

Particle size distribution can be measured by any suitable technique, such as imaging, dynamic light scattering, hydrodynamic fluid fractionation, disk centrifugation, and the like. Particle size analysis by disk centrifugation is the preferred assay. Disc centrifugation uses centrifugal sedimentation to generate a gradient of particles based on size, since larger particles are centrifuged faster than smaller particles. Measure light intensity at the edge of the centrifuge disc as a function of centrifugation time and convert the optical signal into a particle size distribution.

The particle size distribution can be quantified as the weight percentage of particles having a size less than a certain size. For example, the parameter D99 represents a particle diameter of 99% by weight of all the slurry particles having a particle diameter of D99 or less. D50 represents a particle diameter of 50% by weight of all the slurry particles having a particle diameter of D50 or less. Similarly, parameters such as D5, D10, D75, D90, D95, etc. may also be defined.

The D50 of the ceria coated silica particles may range from 10 nm to 500 nm, preferably from 15 nm to 250 nm, more preferably from 20 nm to 200 nm.

In some preferred embodiments, it is desirable to have a broad particle size distribution. The particle size distribution width can be characterized, for example, by calculating the difference between the appropriate high end of the particle size and the middle of the particle size distribution, e.g., D99-D50. This value may also be used to normalize the particle size, such as D50 / (D99-D50). Alternatively, more complex calculations may be performed to measure the polydispersity of the slurry.

In some preferred embodiments, the particle size distribution width characterized by D50 / (D99-D50) is ≤ 1.85, preferably ≤ 1.50, more preferably ≤ 1.30, and most preferably less than 1.25.

In certain embodiments, ceria coated silica particles with different core particle sizes may be mixed to produce a wider particle size distribution.

CMP formulations may also include additives to vary the film-to-film selectivity of the different films, surfactants, dispersants, pH adjusting agents, and biological growth inhibitors.

The pH adjusting agent includes, but is not limited to, sodium hydroxide, cesium hydroxide, potassium hydroxide, cesium hydroxide, ammonium hydroxide, quaternary organic ammonium hydroxide, and combinations thereof.

Chemical additives include, but are not limited to, organic carboxylic acids, amino acids, aminocarboxylic acids, N-acylamino acids and salts thereof; Organic sulfonic acids and their salts; Organic phosphonic acids and their salts; Polymeric carboxylic acids and their salts; Polymeric sulfonic acids and their salts; Polymeric phosphonic acids and their salts; A compound having a functional group selected from the group consisting of an arylamine, an amino alcohol, an aliphatic amine, a heterocyclic amine, a hydroxamic acid, a substituted phenol, a sulfonamide, a thiol, a polyol having a hydroxyl group, and combinations thereof.

The composite particles may comprise single ceria coated silica particles and aggregated ceria coated silica particles; Wherein 99% by weight of the composite particles have an average particle size of less than 250 nm, preferably less than 200 nm, more preferably less than 190 nm.

The ceria coated silica particles may further have an average particle size of less than 150 nm, preferably less than 125 nm, or more preferably less than 110 nm; Where the average particle size is a weighted average of the particle sizes.

The ceria coated silica particles are amorphous silica ceria particles having a surface coated with single crystal ceria nanoparticles.

The change in the size distribution of the multiparticulates under a disintegrative force is less than 10%, preferably less than 5%, or more preferably less than 2%.

When the semiconductor substrate further comprises a nitride layer, the CMP polishing provides more than ten removal selectivities of the at least one oxide layer to the nitride layer. The removal selectivity of TEOS to the silicon nitride layer exceeds 20.

Figure 1 shows the particle size distribution of various ceria coated silica particles by a disk centrifuge particle size analyzer.
Figure 2 shows a schematic diagram of the measurement schematics used and the patterned wafer structure used.
In FIG. 3, the ratio of the trench oxide loss rate to the blanket oxide removal rate is plotted as a function of D50 / (D90-D50) for the CMP slurry with different particles.

DETAILED DESCRIPTION OF THE INVENTION

Composition particle

Composite particles contain primary (or single) particles and primary (or single) aggregate particles. The primary particles have a core particle and numerous nanoparticles covering the surface of the core particle.

The core particles are selected from the group consisting of silica, alumina, titania, zirconia, and polymer particles. The nanoparticles are selected from the group consisting of oxides of zirconium, titanium, iron, manganese, zinc, cerium, yttrium, calcium, magnesium, fluorine, lanthanum and strontium nanoparticles.

One example of composite particles is silica with silica as core particles and ceria as nanoparticles; Each silica core particle has ceria nanoparticles covering its shell. The surface of each silica particle is covered with ceria nanoparticles. The nanoparticles covering the silica core particles may also have a thin layer of a silicon-containing film that partially or completely covers the surface.

Preferred abrasive particles for CMP applications are ceria coated silica particles.

The ceria coated silica particles can be prepared using any suitable method. For example, the method for producing the particles is described in PCT / JP2016 / 060535, JP6358899, JP2017043531, JP2017193692, JP2017206410, JP2017206411, WO18088088, WO18131508, JP2016127139, US6645265, US9447306, JP5979340, WO2005 / 035688 and US2012 / 077419.

Typically, the method of forming composite particles, such as ceria coated silica particles, involves the deposition of a cerium compound on silica core particles followed by a calcination step and a milling step. However, the calcination step results in particle agglomeration. Some of the exemplary methods of reducing the number of aggregate particles include the use of lower calcining conditions such as lower temperature or calcination time, the use of more aggressive milling conditions, the use of dispersants during milling, centrifugation or filtration, , Or the use of any other technique to reduce the number of aggregate particles.

The average particle size (MPS) of the core particles may range from 10 nm to 500 nm, preferably from 20 nm to 200 nm, more preferably from 50 nm to 150 nm. The core particles are larger than the nanoparticles. The MPS of the core particle size in the multiparticulates can be measured by suitable imaging techniques such as transmission electron microscopy imaging.

Particle size distribution can be measured by any suitable technique, such as imaging, dynamic light scattering, hydrodynamic fluid fractionation, disk centrifugation, and the like. Particle size analysis by disk centrifugation is the preferred assay. Disc centrifugation uses centrifugal sedimentation to generate a gradient of particles based on size, since larger particles are centrifuged faster than smaller particles. Measure light intensity at the edge of the centrifuge disc as a function of centrifugation time and convert the optical signal into a particle size distribution.

The particle size distribution can be quantified as the weight percentage of particles having a size less than a certain size. For example, the parameter D99 represents a particle diameter of 99% by weight of all the slurry particles having a particle diameter of D99 or less. D50 represents a particle diameter of 50% by weight of all the slurry particles having a particle diameter of D50 or less. Similarly, parameters such as D5, D10, D75, D90, D95, etc. may also be defined.

In some preferred embodiments, it is desirable to have a broad particle size distribution. The particle size distribution width can be characterized, for example, by calculating the difference between the appropriate high end of the particle size and the middle of the particle size distribution, e.g., D99-D50. This value may also be used to normalize the particle size, such as D50 / (D99-D50). Alternatively, more complex calculations may be performed to measure the polydispersity of the slurry.

In some preferred embodiments, the D50 can range from 10 nm to 500 nm, preferably from 15 nm to 250 nm, more preferably from 20 nm to 200 nm.

In some preferred embodiments, the particle size distribution width characterized by D50 / (D99-D50) is ≤ 1.85, preferably ≤ 1.50, more preferably ≤ 1.30, and most preferably less than 1.25.

In certain embodiments, ceria-coated silica particles having different average particle sizes can be mixed with one another to produce a wider particle size distribution.

Chemical mechanical planarization (CMP)

The purified aggregate particles can be used as abrasive particles in a CMP composition (or CMP slurry, or CMP formulation).

Examples include oxide films, such as various metal oxide films; And an STI (shallow trench isolation) CMP formulation for polishing various nitride films. In STI formulations, formulations comprising silica coated ceria multiparticulates can provide a very high removal rate of the silicon oxide film and a very low removal rate of the silicon nitride polishing stop film. Such slurry formulations include, but are not limited to, thermal oxides, tetraethylorthosilicate (TEOS), high density plasma (HDP) oxide, high aspect ratio process (HARP) film, fluoride oxide film, doped oxide film, organosilicate glass ) Low-K dielectric films, spin-on glass (SOG), polymer films, flowable chemical vapor deposition (CVD) films, optical glass, and display glass.

The formulation may also be used in a stop-and-in-film application where the polishing is stopped once the topography is removed, and a flat surface is realized. Alternatively, the formulation may be used in applications where the bulk film is polished and suspended in the stopper layer. These formulations can be used in a variety of applications including but not limited to shallow trench isolation (STI), interlayer dielectric (ILD) polishing, intermetal dielectric (IMD) polishing, silicon penetrating electrode (TSV) polishing, poly- Si or amorphous- Ge films, and III-V semiconductor films.

The formulation may also be used in any other application, such as glass polishing or solar wafer processing, or wafer grinding where high removal rates are desired.

In certain embodiments, the polishing agent may be used to polish a silicon oxide film at a polishing rate of greater than 2000 Angstroms per minute.

In some other embodiments, the ratio of the TEOS removal rate to the high density plasma silicon oxide film is? 1, or more preferably less than 0.9, or most preferably, less than 0.8.

Another aspect of the use of ceria coated silica particles is that they do not degrade under an abrasive force. There is a hypothesis that if the particles retain their original particle size characteristics without breaking the particles under the action of abrasive forces (i.e., degradation forces), the removal rate will remain high. On the other hand, if the particles are degraded under the abrasive force, the removal rate is reduced because the ceria nanoparticles on the surface which cause the high removal rate can be peeled off. Destruction of the particles can also result in irregularly shaped particles which can have undesirable effects on scratch defects.

The use of such stable particles in CMP slurry formulations allows for more effective use of abrasive forces for film material removal and also prevents the occurrence of any irregular shapes that contribute to scratch defects.

Since advanced CMP applications require very low levels of metal, such as sodium, on the dielectric surface after polishing, it is desirable to have very low trace metals, especially sodium, in the slurry formulation. In certain preferred embodiments, the formulation comprises ceria coated silica particles having a sodium impurity level of less than 5 ppm, more preferably less than 1 ppm, most preferably less than 0.5 ppm, relative to each percent of the particles in the formulation .

The CMP composition comprises purified multiparticulates as abrasive particles, the remainder being water, a polar solvent and a water-soluble solvent selected from the group consisting of a mixture of water and a polar solvent; Wherein the polar solvent is selected from the group consisting of alcohols, ethers, ketones or other polar reagents; The pH of the CMP composition ranges from about 2 to about 12.

The abrasive is present in an amount of 0.01 wt% to 20 wt%, preferably 0.05 wt% to 5 wt%, more preferably about 0.1 wt% to about 1 wt%.

Chemical additives include, but are not limited to, organic carboxylic acids, amino acids, aminocarboxylic acids, N-acylamino acids and their salts; Organic sulfonic acids and their salts; Organic phosphonic acids and their salts; Polymeric carboxylic acids and their salts; Polymeric sulfonic acids and their salts; Polymeric phosphonic acids and their salts; A compound having a functional group selected from the group consisting of an arylamine, an amino alcohol, an aliphatic amine, a heterocyclic amine, a hydroxamic acid, a substituted phenol, a sulfonamide, a thiol, a polyol having a hydroxyl group, and combinations thereof.

The amount of chemical additive ranges from about 0.1 ppm (or 0.000001 wt%) to 5 wt%, relative to the total weight of the barrier CMP composition. The preferred range is about 200 ppm (or 0.02 wt%) to 1.0 wt%, with a more preferred range being about 500 ppm (or 0.05 wt%) to 0.5 wt%.

The pH-adjusting agent includes, but is not limited to, sodium hydroxide, cesium hydroxide, potassium hydroxide, cesium hydroxide, ammonium hydroxide, quaternary ammonium hydroxides such as tetramethylammonium hydroxide and mixtures thereof.

The amount of pH-adjusting agent ranges from about 0.0001% to about 5% by weight relative to the total weight of the CMP composition. A preferred range is about 0.0005 wt% to about 1 wt%, and a more preferred range is about 0.0005 wt% to about 0.5 wt%.

The pH of the CMP composition is from 2 to about 12; Preferably from about 3.5 to about 10; More preferably from about 4 to about 7.

In the case of certain CMP applications, such as shallow trench isolation (STI) or oxide polishing for 3D-NAND devices, it is desirable to reduce the loss of silicon nitride stop layers as well as to reduce dishing in the oxide line features, , Or most preferably 4-7. ≪ RTI ID = 0.0 > [0031] < / RTI > For certain applications, such as barrier metal polishing, the preferred pH range may be 5-12, or more preferably 8-11.

The CMP composition may comprise a surfactant or a mixture of surfactants. Surfactants a). Nonionic surfactants, b). Anionic surfactants, c). Cationic surfactants, d). Amphoteric surfactants, and mixtures thereof.

Nonionic surfactants include, but are not limited to, long chain alcohols, ethoxylated alcohols, ethoxylated acetylenic diol surfactants, polyethylene glycol alkyl ethers, propylene glycol alkyl ethers, glucoside alkyl ethers, polyethylene glycol octylphenyl ethers, polyethylene glycol alkyl phenyl ethers , Glycerol alkyl esters, polyoxyethylene glycol sorbitone alkyl esters, sorbiton alkyl esters, cocamide monoethanolamine, cocamide diethanolamine dodecyldimethylamine oxide, block copolymers of polyethylene glycol and polypropylene glycol, Gt; < RTI ID = 0.0 > fluoro < / RTI > surfactants. The molecular weight of the surfactant may range from hundreds to millions. The viscosity of these materials also has a very wide distribution.

Anionic surfactants include, but are not limited to, salts with suitable hydrophobic tail, such as alkyl carboxylates, alkyl polyacrylates, alkyl sulfates, alkyl phosphates, alkyl bicarboxylates, alkyl bisphosphates, alkyl biphosphates such as alkoxy Substituted alkylsulfates, substituted arylsulfates, substituted arylsulfates, alkylsulfates, carboxylates, alkoxysulfates, alkoxyphosphates, alkoxybicarboxylates, alkoxybisulfates, alkoxybiphosphates such as substituted arylcarboxylates, Substituted aryl bisulfates, substituted aryl bisphosphates, and the like. Counter ions of this type of surface wetting agent include, but are not limited to, potassium, ammonium, and other cations. The molecular weight of the anionic surface wetting agent ranges from hundreds to hundreds of thousands.

The cationic surface wetting agent retains positive net charge in most of the molecular skeleton. Cationic surfactants are typically halides of molecules including hydrophobic chains and a cationic charge center, such as amines, quaternary ammonium, benzylic alkionium and alkylpyridinium ions.

However, in another embodiment, the surfactant can be an amphoteric surface wetting agent having both positive (cationic) and negative (anionic) charges on the main molecular chain and counter counter ions thereof. The cationic moiety is based on a primary, secondary or tertiary amine, or quaternary ammonium cation. The anionic moiety may be more variable, as in the sultaine CHAPS (3 - [(3-cholamidopropyl) dimethylammonio] -1-propanesulfonate) and cocamidopropylhydroxysultain, . Betaines, such as cocamidopropyl betaine, have carboxylates with ammonium. Some amphoteric surfactants may have a phosphate anion with an amine or ammonium, such as phosphatidyl phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine and sphingomyelin.

Examples of surfactants include, but are not limited to, dodecylsulfate sodium salt, sodium lauryl sulfate, dodecylsulfate ammonium salt, secondary alkanesulfonate, alcohol ethoxylate, acetylenic surfactant, and any combination thereof . Examples of suitable commercially available surfactants include TRITON ^TM of a surfactant manufactured by Dow Chemicals, Tergitol ^TM, DOWFAX ^TM family and SUIRFYNOL ^TM manufactured by Air Products and Chemicals, DYNOL ^TM , Zetasperse ^TM , Nonidet ^TM , and Tomadol ^TM surfactant family. Suitable surfactants among the surfactants may also include polymers comprising ethylene oxide (EO) and propylene oxide (PO) groups. An example of an EO-PO polymer is Tetronic ^TM 90R4 from BASF Chemicals.

Other surfactants having the action of dispersants and / or wetting agents include, but are not limited to, polymeric compounds that can have anionic or cationic, or nonionic, or zwitterionic properties. Examples are polymers / copolymers containing functional groups such as acrylic acid, maleic acid, sulfonic acid, vinylic acid, ethylene oxide, and the like.

The amount of surfactant ranges from about 0.0001% to about 10% by weight relative to the total weight of the CMP composition. A preferred range is about 0.001 wt% to about 1 wt%, and a more preferred range is about 0.005 wt% to about 0.1 wt%.

The formulations may also include water-soluble polymers which may include anionic or cationic or non-ionic or a combination of groups. The polymer / copolymer has a molecular weight in the range of more than 1,000, preferably 10,000-4,000,000, more preferably 50,000-2,000,000. Polymers include, but are not limited to, poly (acrylic acid), poly (methacrylic acid), poly (2-acrylamido-2-methyl-1-propanesulfonic acid, carboxymethylcellulose, methylcellulose, - (1-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate). The polymer concentration in the CMP formulation may be from 0.001% to 5% by weight, or more preferably from 0.005% To about 2 wt%, or most preferably from about 0.01 wt% to about 1 wt%.

The chelator or chelating ligand may be used to enhance the affinity of the chelating ligand of the metal cation in applications including, in particular, polishing of metallic films. Chelating agents can also be used to prevent the accumulation of metal ions on the pad which leads to instability of pad dyeing and removal rates. Suitable chelating or chelating ligands include, but are not limited to, benzenesulfonic acid, 4-tolylsulfonic acid, 2,4-diamino-benzosulfonic acid and the like, and also nonaromatic organic acids such as itaconic acid, malic acid, malonic acid , Tartaric acid, citric acid, oxalic acid, gluconic acid, lactic acid, mandelic acid or salts thereof. The amount of chelator or chelating ligand is from about 0.01% to about 3.0% by weight relative to the total weight of the CMP composition; Preferably from about 0.4% to about 1.5% by weight.

The polishing composition may further comprise a corrosion inhibitor for metal polishing applications. Suitable corrosion inhibitors include, but are not limited to, benzotriazole (BTA) or BTA derivatives, 3-amino-1,2,4-triazole, 3,5-diamine-1,2,4-triazole, And combinations thereof.

The polishing composition comprises an oxidizing agent. The oxidizing agent may be any suitable oxidizing agent. Suitable oxidizing agents include, but are not limited to, at least one peroxy-compound comprising at least one peroxy group (O). Suitable peroxy-compounds include, for example, peroxides, persulfates such as monopersulfate and dipersulfate, percarbonates, and acids thereof, and salts thereof, and mixtures thereof. Other suitable oxidizing agents include, for example, oxidized halides (e.g., iodate, periodate, and acids and mixtures thereof), perborates, perborates, percarbonates, peroxy acids Benzoic acid, salts thereof, mixtures thereof, etc.), permanganates, cerium compounds, ferricyanides (e.g., potassium ferricyanide), mixtures thereof and the like.

The CMP composition may include a biological growth inhibitor or preservative to prevent bacterial and fungal growth during storage.

Biological growth inhibitors include, but are not limited to, tetramethylammonium chloride, tetraethylammonium chloride, tetrapropylammonium chloride, alkylbenzyldimethylammonium chloride and alkylbenzyldimethylammonium hydroxide wherein the alkyl chain has from 1 to about 20 carbon atoms Range, including sodium chlorite and sodium hypochlorite.

Some commercially available preservatives include the KATHON ^TM and NEOLENE ^TM product families of Dow Chemicals and the Preventol ^TM family of Lanxess. U.S. Patent No. 5,230,833 (Romberger et al.) And U.S. Patent Application No. US 20020025762. The contents of which are incorporated herein by reference in their entirety.

The preparation may be made into a concentrate and diluted at the time of use. Alternatively, the agent may be made up of two or more components and mixed at the time of use.

parameter:

Å: Angstrom - length unit

BP: back pressure, psi unit

CMP: chemical mechanical planarization = chemical mechanical polishing

CS: Carrier speed

DF: Downforce: Pressure applied during CMP, in psi

min: minutes

ml: milliliter

mV: millivolt

psi: pounds per square inch

PS: Platen rotational speed of the polishing tool, rpm (revolutions per minute)

SF: polishing composition flow, ml / min

Oxide films by chemical vapor deposition (CVD) using tetraethyl orthosilicate as TEOS - precursor

HDP-oxide film produced by the HDP (High Density Plasma) technique

SiN film - Silicon nitride film

Removal Rate and Selectivity

Removal rate (RR) = (film thickness before polishing-film thickness after polishing) / polishing time.

In a subsequent example, the slurry formulation uses water as the remainder of the slurry formulation. All percentages are weight percentages unless otherwise indicated.

Working Example

CMP Polisher: A 200 mm wafer polisher Mirra, manufactured by Applied Materials, and Polishing Pad IC1010 pad supplied by Dow Corporation, were used in the CMP process.

Ammonium polyacrylate (molecular weight 15000-18000), purchased from Kao chemicals, under the trade name EK-1.

The pH of the CMP formulation was adjusted to 5 using ammonium hydroxide.

Particle size distribution measurements were performed using a disk centrifuge particle size analyzer (DC24000 UHR from CPS Instruments). The particle size distribution curve was generated based on an estimate that the particle size density of the multiparticulate was 3.64 gm / cm ³ when calculated based on the composition of the particles.

Example 1

Four different types of ceria coated silica abrasive grains were obtained from JGC & C Corporation (Japan). The particle size distributions of these four particles are summarized in Table 1 below.

Figure 1 shows the particle size distribution of the particles.

There were a plurality of peaks in the particle size distribution plot shown in Fig. Each peak corresponds to a cluster formed by agglomerates of two or more single primary particles. Particles B, C, and D were prepared using a process to tightly control the particle size distribution with two particle size peaks indicating that most clusters have no more than two primary particles. On the other hand, the particles A produced using different processes have a very broad size distribution with four peaks indicating the presence of a particle size cluster comprising two or more primary particles.

Example 2

Polishing was performed on a mummer polishing machine manufactured by Applied Materials. Polishing was performed by in-situ pad conditioning at 3.7 psi, 87 RPM table speed 93 RPM head speed, 200 ml / min slurry flow rate, 6 lb down force.

The particles described in Example 1 were treated separately with a CMP polishing slurry containing 0.185 wt% abrasive grains, 0.14 wt% ammonium polyacrylate (MW about 16000-18000), pH adjusted to 5.45 using ammonium hydroxide, Lt; / RTI >

Table 2 below summarizes the removal rates of the different films obtained by polishing with a CMP polishing slurry.

It is clear that the particle size and particle size distribution differently affect the HDP silicon dioxide film and the TEOS film even though both films contain essentially silicon oxide films.

Particle A with a broader particle size distribution has been shown to provide a much higher removal rate for HDP silicon dioxide films as compared to particles of similar size with a narrower particle size distribution.

Particles D with smaller particle sizes were similarly found to provide higher removal rates for HDP silicon dioxide films compared to TEOS films.

Particles B and C were relatively insensitive to polishing of HDP silicon dioxide films or TEOS films.

Thus, a combination of a smaller particle size and a broader size distribution can help preferentially polish the HDP silicon dioxide film.

Example 3

In this example, the effect of abrasive particles on the sensitivity of superficial or line dishing was measured.

The wafers patterned with the MIT864 pattern were used for polishing. First, the wafer was polished with a calcined ceria slurry (STI2100 of Versum material) to completely remove the HDP oxide from the surface area. The wafer was then polished twice with a polishing time of 60 seconds. After each polishing step, the residual SiN thickness of the surface region and the HDP oxide thickness of the trench region were measured using ellipsometry techniques. Based on this data, the ultimate sensitivity was calculated by dividing the tritium oxide loss rate (pattern removal rate) by the HDP oxide blanket oxide removal rate. A higher trench loss relative to the blanket oxide ratio corresponds to a higher intrinsic sensitivity to undesirable dishing.

FIG. 2 shows a wafer stack before and after polishing, and a method for calculating the pattern removal rate is described.

3, the ratio of the trench oxide loss rate to the blanket oxide removal rate is plotted as a function of D50 / (D90-D50) for the CMP slurry with different particles.

Particles D with smaller particle size distribution (e.g., size distribution of D50 / (D90-D50) = 1.27) are proved to form lower imperfections. Also, as the particle size increases, the dishing for the larger 100 micron feature becomes worse.

Particles A having a broader particle distribution (e.g., D50 / (D90-D50) = 1.07) also exhibited significantly lower impermeability than particles B of similar size. Dishing in a CMP slurry made from Particle A also appeared to be line-width insensitive.

The trench loss of the wide 100 micron feature is comparable to the highly desirable 50 micron feature.

The foregoing description of the embodiments and embodiments should be taken as illustrative rather than restrictive, as defined by the claims. As will be readily appreciated, many variations and combinations of the presented features can be utilized without departing from the invention as set forth in the claims. Such variations are intended to be included within the scope of the following claims.

Claims (23)

Chemical mechanical planarization (CMP) As a polishing composition,
(1) core particles selected from the group consisting of silica, alumina, titania, zirconia, polymer particles and combinations thereof; And nanoparticles selected from the group consisting of oxides of zirconium, titanium, iron, manganese, zinc, cerium, yttrium, calcium, magnesium, fluorine, lanthanum and strontium nanoparticles and combinations thereof, D50 / (D99-D50)? 1.85, wherein D99 is a particle size to which 99% by weight of the composite particles belong, and D50 is a composite particle having a particle size to which 50% weight%;
(2) a water-soluble solvent selected from the group consisting of water, a polar solvent and a mixture of water and a polar solvent, wherein the polar solvent is selected from the group consisting of alcohols, ethers, ketones or other polar reagents;
(3) a pH of the CMP composition ranging from about 2 to about 12
And, optionally,
(4) 0.0001 wt% to about 5 wt% of a pH adjusting agent selected from the group consisting of sodium hydroxide, cesium hydroxide, potassium hydroxide, cesium hydroxide, ammonium hydroxide, quaternary organic ammonium hydroxide, and combinations thereof;
(5) organic carboxylic acids, amino acids, aminocarboxylic acids, N-acylamino acids and salts thereof; Organic sulfonic acids and their salts; Organic phosphonic acids and their salts; Polymeric carboxylic acids and their salts; Polymeric sulfonic acids and their salts; Polymeric phosphonic acids and their salts; Selected from the group consisting of compounds having functional groups selected from the group consisting of arylamine, aminoalcohol, aliphatic amine, heterocyclic amine, hydroxamic acid, substituted phenol, sulfonamide, thiol, polyol having hydroxyl group and combinations thereof 0.000001 wt% to 5 wt% of a chemical additive;
(6) a). Nonionic surface wetting agents, b). Anionic surface wetting agent, c). Cationic surface wetting agents, d). From about 0.0001 wt.% To about 10 wt.% Of a surfactant selected from the group consisting of amphoteric surface wetting agents, and mixtures thereof;
(7) 0.01 to 3.0% by weight of chelator;
(8) corrosion inhibitors;
(9) an oxidizing agent; And
(10) Biological growth inhibitors
(CMP) < / RTI > The chemical mechanical planarization (CMP) polishing composition of claim 1, wherein the composite particles comprise silica core particles and ceria nanoparticles, and the composite particles are ceria coated silica particles. The chemical mechanical planarization (CMP) polishing composition of claim 1, wherein the composite particles have a D50 of 20 nm to 200 nm. The chemical mechanical planarization (CMP) polishing composition of claim 1, wherein the composite particles have a particle size distribution of D50 / (D99-D50)? 1.50. The chemical mechanical planarization (CMP) polishing composition of claim 1, wherein the composite particles have a particle size distribution of D50 / (D99-D50)? 1.30. The method of claim 1, wherein the CMP polishing composition comprises ceria coated silica particles; Polyacrylates (molecular weight 16000-18000); And a pH of 4-7. ≪ Desc / Clms Page number 24 > 4. The composition of claim 1, wherein the CMP polishing composition comprises ceria coated silica particles having a particle size distribution of D50 / (D99-D50) <1.50; Polyacrylates (molecular weight 16000-18000); And a pH of 4-7. ≪ Desc / Clms Page number 24 > 7. The polishing composition of claim 1, wherein the CMP polishing composition comprises: ceria coated silica particles having a particle size distribution of D50 / (D99-D50)? 1.30; Polyacrylates (molecular weight 16000-18000); And a pH of 4-7. ≪ Desc / Clms Page number 24 > A polishing method for chemical mechanical planarization (CMP) of a semiconductor substrate comprising at least one surface having at least one oxide layer,
a) contacting at least one oxide layer with a polishing pad;
b) as a CMP polishing composition,
(1) core particles selected from the group consisting of silica, alumina, titania, zirconia, polymer particles and combinations thereof; And nanoparticles selected from the group consisting of oxides of zirconium, titanium, iron, manganese, zinc, cerium, yttrium, calcium, magnesium, fluorine, lanthanum and strontium nanoparticles and combinations thereof, D50 / (D99-D50)? 1.85, wherein D99 is a particle size to which 99% by weight of the composite particles belong, and D50 is a composite particle having a particle size to which 50% weight%;
(2) a water-soluble solvent selected from the group consisting of water, a polar solvent and a mixture of water and a polar solvent, wherein the polar solvent is selected from the group consisting of alcohols, ethers, ketones or other polar reagents;
(3) a pH of the CMP composition ranging from about 2 to about 12
And, optionally,
(4) 0.0001 wt% to about 5 wt% of a pH adjusting agent selected from the group consisting of sodium hydroxide, cesium hydroxide, potassium hydroxide, cesium hydroxide, ammonium hydroxide, quaternary organic ammonium hydroxide, and combinations thereof;
(5) organic carboxylic acids, amino acids, aminocarboxylic acids, N-acylamino acids and salts thereof; Organic sulfonic acids and their salts; Organic phosphonic acids and their salts; Polymeric carboxylic acids and their salts; Polymeric sulfonic acids and their salts; Polymeric phosphonic acids and their salts; Selected from the group consisting of compounds having functional groups selected from the group consisting of arylamine, aminoalcohol, aliphatic amine, heterocyclic amine, hydroxamic acid, substituted phenol, sulfonamide, thiol, polyol having hydroxyl group and combinations thereof 0.000001 wt% to 5 wt% of a chemical additive;
(6) a). Nonionic surface wetting agents, b). Anionic surface wetting agent, c). Cationic surface wetting agents, d). From about 0.0001 wt.% To about 10 wt.% Of a surfactant selected from the group consisting of amphoteric surface wetting agents, and mixtures thereof;
(7) 0.01 to 3.0% by weight of chelator;
(8) corrosion inhibitors;
(9) an oxidizing agent; And
(10) Biological growth inhibitors
≪ RTI ID = 0.0 > CMP < / RTI > And
c) polishing at least one oxide layer with a CMP polishing composition
&Lt; / RTI &gt; The polishing method according to claim 9, wherein the composite particles comprise silica core particles and ceria nanoparticles, and the composite particles are ceria-coated silica particles. The polishing method according to claim 9, wherein the composite particles have a particle size distribution of D50 / (D99-D50)? 1.50. The polishing method according to claim 9, wherein the composite particles have a particle size distribution of D50 / (D99-D50)? 1.30. 9. The method of claim 8, wherein the CMP polishing composition comprises ceria coated silica particles; Polyacrylates (molecular weight 16000-18000); And a pH of 4-7. 10. The method of claim 9, wherein the CMP polishing composition comprises ceria coated silica particles having a particle size distribution of D50 / (D99-D50) &lt;1.50; Polyacrylates (molecular weight 16000-18000); And a pH of 4-7. 10. The method of claim 9, wherein the CMP polishing composition comprises ceria-coated silica particles having a particle size distribution of D50 / (D99-D50) &lt; = 1.30; Polyacrylates (molecular weight 16000-18000); And a pH of 4-7. The polishing method according to claim 9, wherein the ratio of the removal ratio of TEOS to the removal rate of the high density plasma (HDP) silicon dioxide film is < As a system for chemical mechanical planarization,
A semiconductor substrate comprising at least one surface having at least one oxide layer;
Polishing pad; And
As a CMP polishing composition,
(1) core particles selected from the group consisting of silica, alumina, titania, zirconia, polymer particles and combinations thereof; And nanoparticles selected from the group consisting of oxides of zirconium, titanium, iron, manganese, zinc, cerium, yttrium, calcium, magnesium, fluorine, lanthanum and strontium nanoparticles and combinations thereof, D50 / (D99-D50)? 1.85, wherein D99 is a particle size to which 99% by weight of the composite particles belong, and D50 is a composite particle having a particle size to which 50% weight%;
(2) a water-soluble solvent selected from the group consisting of water, a polar solvent and a mixture of water and a polar solvent, wherein the polar solvent is selected from the group consisting of alcohols, ethers, ketones or other polar reagents;
(3) a pH of the CMP composition ranging from about 2 to about 12
And, optionally,
(4) 0.0001 wt% to about 5 wt% of a pH adjusting agent selected from the group consisting of sodium hydroxide, cesium hydroxide, potassium hydroxide, cesium hydroxide, ammonium hydroxide, quaternary organic ammonium hydroxide, and combinations thereof;
(5) organic carboxylic acids, amino acids, aminocarboxylic acids, N-acylamino acids and salts thereof; Organic sulfonic acids and their salts; Organic phosphonic acids and their salts; Polymeric carboxylic acids and their salts; Polymeric sulfonic acids and their salts; Polymeric phosphonic acids and their salts; Selected from the group consisting of compounds having functional groups selected from the group consisting of arylamine, aminoalcohol, aliphatic amine, heterocyclic amine, hydroxamic acid, substituted phenol, sulfonamide, thiol, polyol having hydroxyl group and combinations thereof 0.000001 wt% to 5.0 wt% of a chemical additive;
(6) a). Nonionic surface wetting agents, b). Anionic surface wetting agent, c). Cationic surface wetting agents, d). From about 0.0001 wt.% To about 10 wt.% Of a surfactant selected from the group consisting of amphoteric surface wetting agents, and mixtures thereof;
(7) 0.01 to 3.0% by weight of chelator;
(8) corrosion inhibitors;
(9) an oxidizing agent; And
(10) Biological growth inhibitors
CMP &lt; / RTI &gt;
Wherein at least one oxide layer is in contact with the polishing pad and the polishing composition. 18. The system of claim 17, wherein the composite particles comprise silica core particles and ceria nanoparticles, or the composite particles are ceria coated silica particles. 18. The system of claim 17, wherein the composite particles have a particle size distribution of D50 / (D99-D50)? 1.50. 17. The system of claim 16, wherein the composite particles have a particle size distribution of D50 / (D99-D50) &amp;le; 1.30. 18. The method of claim 17, wherein the CMP polishing composition comprises ceria coated silica particles; Polyacrylates (molecular weight 16000-18000); And a pH of 4-7. 18. The method of claim 17, wherein the CMP polishing composition comprises ceria coated silica particles having a particle size distribution of D50 / (D99-D50) &lt; = 1.50; Polyacrylates (molecular weight 16000-18000); And a pH of 4-7. 18. The method of claim 17, wherein the CMP polishing composition comprises: ceria coated silica particles having a particle size distribution of D50 / (D99-D50)? 1.30; Polyacrylates (molecular weight 16000-18000); And a pH of 4-7.

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